Curling iron



FIG. 1 is a front elevational view of a curling iron embodying my new design and depicted in a closed position, the rear elevational view being the mirror image thereof;

FIG. 2 is a top plan view thereof;

FIG. 3 is a bottom plan view thereof;

FIG. 4 is a left side elevational view thereof;

FIG. 5 is a right side elevational view thereof; and

FIG. 6 is a perspective view of the design in an open position.

The broken line showing a power cord is for illustrative purposes only and forms no part of the claimed design. 

The ornamental design for a curling iron, as shown and described. 